This invention relates to a camera having interchangeable lenses and a built-in strobe, and more particularly to a camera having a built-in strobe capable of determining that an object to be photographed is not effectively irradiated by light from the built-in strobe due to an outer shape and a focal length of the particular photographic lens attached to the camera.
One method of photographing an poorly illuminated object is to use a flash strobe. Cameras utilizing strobes are divided into two types; one has a strobe built into the camera while the other has a construction onto which a separately prepared strobe is mounted.
A typical camera having a built-in strobe is a lens shutter camera. With this kind of camera, an outer shape and focal length are not greatly changed. Therefore, it is an easy matter to bring the strobe and the lens into a proper relation in a manner that a photographing zone of the camera or a field of view of the lens is within a spreading zone of the strobe light and the outer shape of the lens does not obstruct the strobe light. Accordingly, there is no trouble in taking flash photography in case of a lens shutter cameras.
On the other hand, using cameras with interchangeable lenses, various lenses are used according to the photographing purpose. Among these photographic lenses, there are lens having large diameters, long overall lengths or different fields of view due to different focal lengths. In the case where a strobe is built into a camera body of a lens interchangeable camera, if the photographic lens mounted on the camera body has a large diameter or a long overall length, part or all of the strobe light incident upon an object may be obstructed by the photographic lens itself. Moreover, in the case of a wide angle lens that is mounted on the camera, a spreading zone of the strobe light may be often narrower than the field of view of the lens.
In the event that photographing if effected under such an objectionable conditions, a required picture could not be obtained, while films are superfluously consumed in any case.